1. Field of the Invention
The present invention relates to an excreta treating material made of absorbent granules mainly containing compressively granulated organic fiber, a production method thereof, and an extrusion type compressive granulating apparatus thereof.
2. Description of the Related Art
Regarding an excreta treating material, it is required that absorbent granules in a urine area are rapidly disintegrated and aggregated after absorbing urine from the viewpoint of the merchantable quality (this aggregation helps a user to determine whether the granules are used or not, and therefore it makes easy for a user to replace the used ones with new granules).
In the past, in order to meet such requirement, a method has been adopted which applies a material formed by mixing a paper powder and starch, CMC, or absorbent polymer onto an outer peripheral surface of an absorbent granule that is compressively granulated under hydration to form a coating layer on the surface, and bonds the adjacent granules to each other by disintegrating the coating layer when absorbing urine so that the granules can be aggregated. However, in this method, there are problems in that manufacturing cost increases due to a manufacturing process necessary to form the absorbent granule as a double structure, and the coating layer is peeled off the coated surface (for example, refer to Japanese Patent Application Laid-Open (JP-A) No. 2008-278826).
On the other hand, as a method of solving a problem of degradation in disintegration and aggregation of the granule without forming the coating layer having the above-described problem, there is known a method which adds oil, wax, or silicon to a raw material mainly containing organic fiber, and kneads and compresses the raw material to be granulated so that the organic fibers may be satisfactorily separated from each other when absorbing urine and are disintegrated and aggregated (for example, refer to JP-A No. 2008-136454).
However, in the above-described method, the featured absorbing property of the excreta treating material may be degraded due to the oil or the like added to the raw material, manufacturing cost may increase due to the use of oil or the like, and a fire is likely to occur during a drying process.